BROOKLYN (PIX11) — A group of assailants sucker punched a 74-year-old man in the face and then stole $15 from him last week in Brooklyn, police said.

A 74-year-old man was walking on Sutter Avenue on Feb.1 when a group of people, two men, and one woman, walked up from behind and punched him in the face around 7:06 p.m., police said.

The attack knocked the man onto the ground, leaving a gash to his upper lip, authorities said. The suspects then snatched $15 from the victim’s pocket and ran away, police said.

The victim was transported to a hospital in what authorities described as stable condition.

It is unclear what led to the attack and the investigation is ongoing.

Anyone with information in regard to this incident is asked to call the NYPD’s Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782). The public can also submit their tips by logging onto the CrimeStoppers website at https://crimestoppers.nypdonline.org/ or on Twitter @NYPDTips.